Motor-driven blower mounted on pipe



June I,- 1954 F. J. BRUMME MOTOR-DRIVEN BLOWER MOUNTED ON PIPE 2 Sheets$heec 1 Filed June 16, 1949 INVENTOR. EQ Z/f rffirzznzzze BY Patented June 1,- 1954 Frank J. Brumme; Bloomingtom lll;

ApplicationJ une. 16, 1949, Serial No. 99,527

2 Claims. (Cl. 230-117) My;.i' invention-' relates tow a pipe with 1a fan therein for' enforcing circulation throughthe pipe I and.has reference more particularly to a con-. structio'n'wherein a straight length of pipe has a propeller type fantherein directlyconnected to anyoperatin'g motor which is outside the pipe.

oftentimes when hot air or gases are conducted throughf'pipe it is desirable to provide a fan thereinto increase-circulation, for example, in.

the. exhaust pipe from a heater or furnace, when the" natural draft is insuflicient.

Itis important, however, to locate the motor outsidejfthetflue so as .to avoid exposure thereof.

toheat andsoot which wouldbe likely to damage the motor orinterfere. withthe operation thereof. Moreover, it ..'is desirable for simplicity of con.-. struction and eflic'iency ofoperation. to provide a direct connection of the. fan with the motor shaft.

and to .avoid location of. bearings within th flue where;.the'y are not readily. accessible and..,are

exposed to the. heatanclsoottherein...

Generally',1it is necessary ordesirable, to install such draft increasing fansin a straight lengthof the pipe, andno. simple and satisfactory construction has .been available. heretofore byv which a propeller type of fan isapplicable to such straight lengths, of pipe.

It is an object of my invention to provide an improvecl.-;construction of, draft-increasing. 'fan in a straight length of. pipe.- It is another object of my invention to locate the motor for such draft-increasing fan at the exterior of the pipe; Itlis' a further object'of myinvention to permit direct connectionof a propeller-type fan withinthepipe to a motor-at-the exterior thereof-9' It is a; still further object ofmy invention to avoid locating any 1 bearings in the pipe where they would be exposed to heat-andsoot; And,*in general; ityis the object of my invention to provide a simple inexpensive, and 1 efficient straight pipe;- structure with a draftincreasingpropeller fantlierein, :thse andother-- objects being accomplishedfasrhereinafterdescribed, reference being" had to the accompanying-drawing.inwhich:

Fig. 1 is a side view of a length of pipe showing my., draft'-increasing fan installed therein;

Fig. 2 is an-enlargedviewon-"the.line 2i-2 of Fi'gi isa view lookingat-the bottommof .the structure of "Fig: "2, but-showing "the pipe and motor supporting bracket mostly in section on the line 33 of Fig. 2.

Fig. 4 is a fragmentary transverse sectional view showing a detail of the pipe construction;

Fig. 5 is a view of a fragmentary portion of the pipe wall;

Fig. 6 is a sideview ofan optional-type.ofppropeller. fan; and

Fig. 7 is anend view of the propellerfan shown in Fig. 6.

While my invention is applicable to any..type of flue or duct in .which it is desired to increase-- the draft or enforce. circulation therethrough,.-itj. is particularly advantageousforuse in connection withsheet metal pipe of the. character commonly. employed for conductin products of combustion. from a furnace, stove, orthe liketothe chimney or stack.

Accordingly, I have shown and described-my invention herein as applied to ,a length, of. stove I pipe I!) of conventional form made of sheet metal and. having one. end. thereof slightly. reducedu'n diameteras at H, beyond an annular external. bead l2,.the other end I3 of said .pipe length .be-N ing. of normal size .beyondanannual internaL. bead M to receive thereinanend I I of another similar pipe to makeup. whatever length of smoke r pipe is required inthe .particular -case..-

The beads 12 and. not only serve as stops to limit the interengagement of the pipelengths but... are designedto reinforcethe pipe. andmaintain 1 the circularity thereof, such reinforcement-being particularly desirable in the present .case .to insure ample rigidity to support theparts mount-e ed on the pipe.

An electric motor. I5 ofpany. suitable type is provided to operate. the. .draft-increasing an. .1 6 and is mounted at anangle with respectto. the.- pipe, I0 by.means.of..a' U-shapedbracket I] which... may be made 'of sheet metal and issecured to the... pipe [0 in any convenient manner, for example-I;

by ,welding,,and inan angular positionthereon as shown-in Fig. 3. Themotor I5 is securedto. the bracketj'flbymeans of bolts l8 and the 1110-. tor shaft 19 extendsltherethrough at a preferred angle ofabout 45 ,"degrees. with. respect to the longitudinal axisof the. pipe.v ill.

The. .draftein'creasing' .fanjfi is .mountedonfianzri extension shaft 20 whichjis Ioonnected to rtheia, motor shaftifl'by means of ,a coupling .2! which... is secured to the shafts" l9 and.-2il. by means-.of.: set screws 22.. The extensionshaft 20=and the 1 coupling- 2| "project. into .the pipe 10 throughrthe 1 opening 23 in the sidewalljof thepipe, the said...- opening 23 beingof. the size necessary.to"permit.

free turning 'of the coupling 2| therein without contact.

The draft-increasing fan I 6 may be of any propeller fan type which will produce circulation in the desired direction when mounted on a shaft projecting obliquely into a cylindrical enclosure. A preferred type of draft-increasingfan is shown in Figs. 2 and 3 wherein the opposed blades 24 and 25 are flat plates disposed at right angles with respect to each other. Each blade 24 and 25 has a stem 26 engaged in its respective end of the sleeve 27 and retained in predetermined position with respect thereto by means of the set screw 28. The said sleeve 27 is mounted on the extension shaft by means of the screw 29.

In the rotation of the fan 16, the blades 24 and move in one half side of the pipe (0 in a direction corresponding to that of the smoke flow through the pipe, for example upwardly in the pipe ll! of Fig. 3, and in the opposite side half of the pipe said blades 24 and 25 move in the revers direction, or downwardly in the pipe of Fig. 3, and said blades are arranged so that each thereof when midway in its movement in the direction of smoke flow is in a plane substantially at right angles to the longitudinal axis of the pipe It in the position in which the blade 25 is shown in Fig. 3, whereas each blade when midway in its movement in said reverse direction is in a plane substantially coinciding or parallel with the longitudinal axis of the pipe in the position in which the blad 24 is shown in Fig. 3. Thus, on the rising portion of its stroke as viewed in Fig. 3, each blade is moving mostly sidewise toward the upper end of the pipe and accordingly imparts substantial thrust of smoke in the direction of smoke circulation through the pipe where as in the descending portion of its stroke, each blade is moving mostly edgewise toward the lower end of the pipe and accordingly has practically no propelling effect on the smoke in that direction.

For the purpose of gaining access to the draftincreasing fan It, an opening 39 may be provided in one wall of the pipe i0 opposite the location of the fan i5, as shown in Figs. 1, 4 and 5. A removable door 31 comprising a curved section of sheet metal, serves to close the opening 30. At each end thereof in the direction of its curvature, the door 3| has a raised portion 32 with a slot 33 leading inwardly from the marginal edge of the door 3|. The raised portion 32 is adapted to fit over the nut 34 which retains the bolt 35 in place. The said bolt 35 is straddled by the slot 33 in the edge of the door 31 when the said door is mounted over the opening 30 in the pipe i9 and the door is held firmly in position by engagement of the raised portions 32 between the nuts 34 and the wing nuts 36. Thus the door 3! may be removed and reinstalled quite conveniently when it is desired to inspect or adjust the draftincreasing fan l6.

"Referring now to Figs. 6 and 7, I have shown another type of draft-increasing fan 37 which has been used effectively in connection with my invention. tially rectangular section of sheet metal with portions curved upwardly, as shown particularly at'38 in Fig. '7 at opposite sides of a diagonal line thereof. This fan 3'! is provided with a hub 39 secured thereto at the center in any convenient manner. The hub 39 has a bore of suitable size to fit on the extension shaft 20 and is secured in place thereon by a set screw 40, with the turned up corners 4| extending in the direction in which the air is to be circulated.

This fan 37 comprises a substan- Such fans and similar fans which are of the type to produce circulation generally in th direction lengthwise of the axis of rotation thereof, are referred to herein as propeller fans.

While I have shown and described my invention in a preferred form, I am aware that various modifications can be made therein without departing from the spirit of my invention, the scope of which is to be determined by the appended claims.

What I claim:

1. An air duct and fan assembly comprising a substantially straight length of pipe, a motor, a motor support which projects from the side of the pipe in a direction oblique to the longitudinal axis of the pipe and is interposed between the motor and pipe and has the motor secured endwise thereto at the outer nd thereof and has the inner end secured directly to the side wall of the pipe, a shaft which is rotated by the motor and supported solely thereby and projects axially therefrom through said support and obliquely into the pipe through the side wall thereof beyond the inner end of said motor support and is spaced apart from and free of contact with said support and pipe, and a fan within the pipe and secured on the shaft to rotate therewith, said support being formed with a space therein between the motor and pipe through which the shaft extends and through which air is circulatable from the exterior of the support.

2. An air duct and fan assembly comprising a substantially straight length of pipe, a motor, a shaft which is rotated by the motor and supported solely thereby and projects axially therefrom obliquely into the pipe through the side wall thereof, a fan within the pipe and secured on the shaft to rotate therewith, and a U-shaped motor support which is interposed between the motor and pipe and projects obliquely from the pipe and has the motor secured endwise thereto at the outer end thereof, said support having a pair of widely spaced legs which are joined together at their outer ends and straddle the shaft and have their inner free ends secured to the side wall of the pipe at widely separated places at opposite sides of the shaft.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 300,384 Mathieu June 17, 1884 1,082,594 Kern Dec. 30, 1913 1,182,863 Toussaint May 9, 1916 1,314,563 Axen Sept. 2, 1919 1,399,617 Hahn 1- Dec. 6, 1921 1,498,789 Drouillard June 24, 1924 1,502,862 Menk July 29, 1924 1,573,973 Lamontagne Feb. 23, 1926 2,179,893 Lyon Nov. 14, 1939 2,276,614 Grapp Mar. 17, 1942 2,282,256 Smelik May 5, 1942 FOREIGN PATENTS Number Country Date 53,550 Netherlands Dec. 15, 1952 470,305 Germany Jan. 9, 1929' 473,579 Germany Mar. 16, 1929 504,020 Germany July 30, 1930 

